diff --git a/packages/vite/src/node/config.ts b/packages/vite/src/node/config.ts
index 8c83bf787896ea..1a79ebaa89fbc3 100644
--- a/packages/vite/src/node/config.ts
+++ b/packages/vite/src/node/config.ts
@@ -117,10 +117,9 @@ export type UserConfigExport =
  * The function receives a {@link ConfigEnv} object that exposes two properties:
  * `command` (either `'build'` or `'serve'`), and `mode`.
  */
-export function defineConfig(config: UserConfig): UserConfig
-export function defineConfig(config: Promise<UserConfig>): Promise<UserConfig>
-export function defineConfig(config: UserConfigExport): UserConfigExport
-export function defineConfig(config: UserConfigExport): UserConfigExport {
+export function defineConfig<Config extends UserConfigExport>(
+  config: Config,
+): Config {
   return config
 }